Welding-associated air pollutants negatively affect the health of exposed workers; however, their molecular mechanisms in causing disease remain largely unclear. Few studies have systematically investigated the systemic toxic effects of welding fumes on humans.
To explore the effects of welding fumes on the plasma metabolome, and to identify biomarkers for risk assessment of welding fume exposure.
The two-stage, self-controlled exploratory study included 11 boilermakers from a 2011 discovery panel and 8 boilermakers from a 2012 validation panel. Plasma samples were collected pre- and post-welding fume exposure and analyzed by chromatography/mass spectrometry.
Eicosapentaenoic or docosapentaenoic acid metabolic changes post-welding were significantly associated with particulate (PM2.5) exposure (p<0.05). The combined analysis by linear mixed-effects model showed that exposure was associated with a statistically significant decline in metabolite change of eicosapentaenoic acid [(95% CI) = −0.013(−0.022∼−0.004); p = 0.005], docosapentaenoic acid n3 [(95% CI) = −0.010(−0.018∼−0.002); p = 0.017], and docosapentaenoic acid n6 [(95% CI) = −0.007(−0.013∼−0.001); p = 0.021]. Pathway analysis identified an association of the unsaturated fatty acid pathway with exposure (pStudy−2011 = 0.025; pStudy−2012 = 0.021; pCombined = 0.009). The functional network built by these fatty acids and their interactive genes contained significant enrichment of genes associated with various diseases, including neoplasms, cardiovascular diseases, and lipid metabolism disorders.
High-dose exposure of metal welding fumes decreases unsaturated fatty acids with an exposure-response relationship. This alteration in fatty acids is a potential biological mediator and biomarker for exposure-related health disorders.
NELL-1 is a novel osteoinductive growth factor that has shown promising results for the regeneration of bone. Moreover, NELL-1 has been used successfully in bone regeneration in the axial, appendicular and calvarial skeleton of both small and large animal models. Despite increasing evidence of NELL-1 efficacy and future usefulness as an alternative to traditional bone graft substitutes, much has yet to be understood regarding the mechanisms of action of this novel protein. The activation of the mitogen-activated protein kinase (MAPK) pathway has been well studied in the setting of growth factor-mediated changes in osteogenic differentiation.
In this study, we provide evidence of the involvement of MAPK signalling pathways in NELL-1-induced terminal osteogenic differentiation of Saos-2 human osteosarcoma cells. Activation of extracellular signal-regulated kinase (ERK1/2), P38 and c-Jun N-terminal kinase (JNK) pathways were screened with MAPK signalling protein array after recombinant human (rh)NELL-1 treatment. Next, the mineralisation and intracellular phosphate levels after rhNELL-1 stimulation were assessed in the presence or absence of specific MAPK inhibitors.
Results showed that rhNELL-1 predominantly increased JNK pathway activation. Moreover, the specific JNK inhibitor SP600125 blocked rhNELL-1-induced mineralisation and intracellular phosphate accumulation, whereas ERK1/2 and P38 inhibitors showed no effect.
Thus, activation of the JNK pathway is necessary to mediate terminal osteogenic differentiation of Saos-2 osteosarcoma cells by rhNELL-1. Future studies will extend these in vitro mechanisms to the in vivo effects of NELL-1 in dealing with orthopaedic defects caused by skeletal malignancies or other aetiologies.
Genome-wide association studies (GWAS) are popular for identifying genetic variants which are associated with disease risk. Many approaches have been proposed to test multiple single nucleotide polymorphisms (SNPs) in a region simultaneously which considering disadvantages of methods in single locus association analysis. Kernel machine based SNP set analysis is more powerful than single locus analysis, which borrows information from SNPs correlated with causal or tag SNPs. Four types of kernel machine functions and principal component based approach (PCA) were also compared. However, given the loss of power caused by low minor allele frequencies (MAF), we conducted an extension work on PCA and used a new method called weighted PCA (wPCA). Comparative analysis was performed for weighted principal component analysis (wPCA), logistic kernel machine based test (LKM) and principal component analysis (PCA) based on SNP set in the case of different minor allele frequencies (MAF) and linkage disequilibrium (LD) structures. We also applied the three methods to analyze two SNP sets extracted from a real GWAS dataset of non-small cell lung cancer in Han Chinese population. Simulation results show that when the MAF of the causal SNP is low, weighted principal component and weighted IBS are more powerful than PCA and other kernel machine functions at different LD structures and different numbers of causal SNPs. Application of the three methods to a real GWAS dataset indicates that wPCA and wIBS have better performance than the linear kernel, IBS kernel and PCA.
Theranostics; carbon dots; chlorin e6 (Ce6); fluorescence imaging; photodynamic therapy
The human SLC25A13 gene encodes citrin, the liver-type mitochondrial aspartate/glutamate carrier isoform 2 (AGC2), and SLC25A13 mutations cause citrin deficiency (CD), a disease entity that encompasses different age-dependant clinical phenotypes such as Adult-onset Citrullinemia Type II (CTLN2) and Neonatal Intrahepatic Cholestasis caused by Citrin Deficiency (NICCD). The analyses of SLC25A13 gene and its protein/mRNA products remain reliable tools for the definitive diagnoses of CD patients, and so far, the SLC25A13 mutation spectrum in Chinese CD patients has not been well-characterized yet.
Methods and Results
By means of direct DNA sequencing, cDNA cloning and SNP analyses, 16 novel pathogenic mutations, including 9 missense, 4 nonsense, 1 splice-site, 1 deletion and 1 large transposal insertion IVS4ins6kb (GenBank accession number KF425758), were identified in CTLN2 or NICCD patients from China, Japan and Malaysia, respectively, making the SLC25A13 variations worldwide reach the total number of 81. A large NICCD cohort of 116 Chinese cases was also established, and the 4 high-frequency mutations contributed a much larger proportion of the mutated alleles in the patients from south China than in those from the north (χ2 = 14.93, P<0.01), with the latitude of 30°N as the geographic dividing line in mainland China.
This paper further enriched the SLC25A13 variation spectrum worldwide, and formed a substantial contribution to the in-depth understanding of the genotypic feature of Chinese CD patients.
Transgenic mice overexpressing SUR1 and gain of function Kir6.2[ΔN30, K185Q] KATP channel subunits, under cardiac α-myosin heavy chain (αMHC) promoter control, demonstrate arrhythmia susceptibility and premature death. Pregnant mice, crossed to carry double transgenic progeny, which harbor high levels of both overexpressed subunits, exhibit the most extreme phenotype and do not deliver any double transgenic pups.
To explore the fetal lethality and embryonic phenotype that result from KATP overexpression, wild type (WT) and KATP overexpressing embryonic cardiomyocytes were isolated, cultured and voltage-clamped using whole cell and excised patch clamp techniques. Whole mount embryonic imaging, Hematoxylin and Eosin (H&E) and α smooth muscle actin (αSMA) immunostaining were used to assess anatomy, histology and cardiac development in KATP overexpressing and WT embryos. Double transgenic embryos developed in utero heart failure and 100% embryonic lethality by 11.5 days post conception (dpc). KATP currents were detectable in both WT and KATP-overexpressing embryonic cardiomyocytes, starting at early stages of cardiac development (9.5 dpc). In contrast to adult cardiomyocytes, WT and KATP-overexpressing embryonic cardiomyocytes exhibit basal and spontaneous KATP current, implying that these channels may be open and active under physiological conditions. At 9.5 dpc, live double transgenic embryos demonstrated normal looping pattern, although all cardiac structures were collapsed, probably representing failed, non-contractile chambers.
In conclusion, KATP channels are present and active in embryonic myocytes, and overexpression causes in utero heart failure and results in embryonic lethality. These results suggest that the KATP channel may have an important physiological role during early cardiac development.
ATP sensitive K channel (KATP); Cardiac development; Heart failure; Embryonic lethality
Aims. This study evaluated feasibility and safety of implanting the polyester-coated nitinol ventricular septal defect occluder (pcVSDO) in the canine model. Methods and Results. VSD models were successfully established by transseptal ventricular septal puncture via the right jugular vein in 15 out of 18 canines. Two types of VSDOs were implanted, either with pcVSDOs (n = 8) as the new type occluder group or with the commercial ventricular septal defect occluders (VSDOs, n = 7, Shanghai Sharp Memory Alloy Co. Ltd.) as the control group. Sheath size was 10 French (10 Fr) in two groups. Then the general state of the canines was observed after implantation. ECG and TTE were performed, respectively, at 7, 30, 90 days of follow-up. The canines were sacrificed at these time points for pathological and scanning electron microscopy examination. The devices were successfully implanted in all 15 canines and were retrievable and repositionable. There was no thrombus formation on the device or occurrence of complete heart block. The pcVSDO surface implanted at day 7 was already covered with neotissue by gross examination, and it completed endothelialization at day 30, while the commercial VSDO was covered with the neotissue in 30th day and the complete endothelialization in 90th day. Conclusion. The study shows that pcVSDO is feasible and safe to close canine VSD model and has good biocompatibility and shorter time of endothelialization.
We present the genome of a cyanosiphovirus (KBS2A) that infects a marine Synechococcus sp. (strain WH7803). Unique to this genome, relative to other sequenced cyanosiphoviruses, is the absence of elements associated with integration into the host chromosome, suggesting this virus may not be able to establish a lysogenic relationship.
Microalgae are promising feedstock for production of lipids, sugars, bioactive compounds and in particular biofuels, yet development of sensitive and reliable phylotyping strategies for microalgae has been hindered by the paucity of phylogenetically closely-related finished genomes.
Using the oleaginous eustigmatophyte Nannochloropsis as a model, we assessed current intragenus phylotyping strategies by producing the complete plastid (pt) and mitochondrial (mt) genomes of seven strains from six Nannochloropsis species. Genes on the pt and mt genomes have been highly conserved in content, size and order, strongly negatively selected and evolving at a rate 33% and 66% of nuclear genomes respectively. Pt genome diversification was driven by asymmetric evolution of two inverted repeats (IRa and IRb): psbV and clpC in IRb are highly conserved whereas their counterparts in IRa exhibit three lineage-associated types of structural polymorphism via duplication or disruption of whole or partial genes. In the mt genomes, however, a single evolution hotspot varies in copy-number of a 3.5 Kb-long, cox1-harboring repeat. The organelle markers (e.g., cox1, cox2, psbA, rbcL and rrn16_mt) and nuclear markers (e.g., ITS2 and 18S) that are widely used for phylogenetic analysis obtained a divergent phylogeny for the seven strains, largely due to low SNP density. A new strategy for intragenus phylotyping of microalgae was thus proposed that includes (i) twelve sequence markers that are of higher sensitivity than ITS2 for interspecies phylogenetic analysis, (ii) multi-locus sequence typing based on rps11_mt-nad4, rps3_mt and cox2-rrn16_mt for intraspecies phylogenetic reconstruction and (iii) several SSR loci for identification of strains within a given species.
This first comprehensive dataset of organelle genomes for a microalgal genus enabled exhaustive assessment and searches of all candidate phylogenetic markers on the organelle genomes. A new strategy for intragenus phylotyping of microalgae was proposed which might be generally applicable to other microalgal genera and should serve as a valuable tool in the expanding algal biotechnology industry.
Nannochloropsis; Plastid phylogenomes; Mitochondrial phylogenomes; Intragenus phylotyping strategy
The dried fruits of Alpinia oxyphylla Miq have been widely used as an herbal medicine for the treatment of diarrhea and enuresis in China. Medicinal chemistry studies revealed that the tepenes, diphenylheptanes and flavones were the main components. Therefore, these three kinds of components should be chosen as the bioactive marker compounds for the quality control of A. oxyphylla fruits. Moreover, multiple active components has been widely recognized to be a more feasible method for the quality control of herbal medicines. This study firstly provided a better method for comprehensive component analysis of A. oxyphylla fruits. Meanwhile, the different harvest time was also evaluated.
The solvent-to-sample ratio was the most important factor comparing with solvent, extraction time and temperature. The highest yield of nine compounds was achieved with 70% ethanol-water and a solvent-to-sample ratio of 20:1 at 60°C for 30 min. The optimized analytical method for ultra fast high performance liquid chromatography (UFLC) was a gradient elution using water containing 0.04‰ formic acid (A) and methanol containing 0.04‰ formic acid (B), at a flow rate of 0.3 mL/min. Using this optimized method, nine compounds were simultaneously separated and quantified by UFLC coupled with tandem electro-spray ionized mass spectrometry (MS/MS).
The contents of the six bioactive compounds were reported in A. oxyphylla for the first time. The contents of nine compounds of different harvest time fruits of A. oxyphylla were assessed under the optimized extraction and UFLC-MS/MS analytical conditions, and the 45-day culture fruit had the highest content levels.
UFLC-MS/MS; Alpinia oxyphylla fruits; Quality control
The SuoQuan formulae containing Fructus Alpiniae Oxyphyllae has been used to combat the urinary incontinence symptoms including frequency, urgency and nocturia for hundreds of years in China. However, the chemical information was not well characterized. The quality control marker constituent only focused on one single compound in the current Chinese Pharmacopeia. Hence it is prudent to identify and quantify the main constituents in this herbal product. This study aimed to analyze the main constituents using ultra-fast performance liquid chromatography coupled to tandem mass spectrometry (UFLC-MS/MS).
Fourteen phytochemicals originated from five chemical classes constituents were identified by comparing the molecular mass, fragmentation pattern and retention time with those of the reference standards. A newly developed UFLC-MS/MS was validated demonstrating that the new assay was valid, reproducible and reliable. This method was successfully applied to simultaneously quantify the fourteen phytochemicals. Notably, the content of these constituents showed significant differences in three pharmaceutical preparations. The major constituent originated from each of chemical class was isolinderalactone, norisoboldine, nootkatone, yakuchinone A and apigenin-4’,7-dimethylther, respectively. The variation among these compounds was more than 1000 times. Furthermore, the significant content variation between the two different Suoquan pills was also observed.
The proposed method is sensitive and reliable; hence it can be used to analyze a variety of SuoQuan formulae products produced by different pharmaceutical manufacturers.
Fructus Alpiniae Oxyphyllae; Radix Linderae; SuoQuan formulae; UFLC-MS/MS; Alkaloids; Diarylheptanoids; Flavonoids; Lactones; Naphthalenone
Saliva diagnostics has become an attractive field utilizing nanotechnology and molecular technologies for pSS (primary Sjögren's syndrome). However, no specific methods have been established. To refine the diagnostic power of the saliva peptide finger print for the early detection of pSS, we screened the expression spectrum of salivary peptides in pSS patients by using mass spectrometry MALDI-TOF-MS (matrix-assisted laser-desorption ionization-time-of-flight MS) combined with magnetic bead. The present study was comprised 12 pSS patients and 13 healthy controls and broken down to two different phases. In the initial ‘exploratory phase’, we enrolled seven pSS patients with eight age- and sex-matched healthy volunteers. Proteomics analysis of the unstimulated salivary samples was conducted to generate proportional peptide mass fingerprints. A diagnostic model was established. The testing cohort of the second ‘validation phase’ was represented by five pSS patients and five age- and sex-matched healthy controls. The diagnostic power of this diagnostic panel was then validated. The results showed seven m/z (mass-to-charge) ratio peaks with significant differences. Five peptides were up-regulated and two down-regulated in the pSS patients compared with matched healthy subjects. In the validation phase, four out of five pSS patients were diagnosed as pSS, and four of the five healthy controls were diagnosed as healthy controls, respectively. Potential biomarkers were also primarily predicted. The novel diagnostic proteomic model with m/z peaks 1068.1 Da, 1196.2 Da, 1738.4 Da, 3375.3 Da, 3429.3 Da, 3449.7 Da and 3490.6 Da is of certain value for early diagnosis of pSS.
mass spectrum; peptidomics; salivary diagnostics; Sjogren’s syndrome (SS); weak cation exchange beads; MALDI-TOF-MS, matrix-assisted laser-desorption ionization-time-of-flight MS; PRP, proline-rich protein; pSS, primary Sjögren’s syndrome; sSS, secondary SS; WS, whole saliva; WCX, weak cation exchange
Non-invasive and quantitative imaging of vascular endothelial growth factor receptor-2 (VEGFR-2) expression levels is highly important in cancer diagnosis, prognosis, and patient management. Although various literature reports have investigated the tumor expression levels of VEGFR-2 using imaging techniques such as positron emission tomography, single-photon emission computed tomography, targeted ultrasound, etc., accurate evaluation of the dynamic microdistribution of VEGFR-2 in vivo with good spatial and temporal resolution remains a major challenge. In this issue of the American Journal of Nuclear Medicine and Molecular Imaging, He at al. reported the use of a VEGFR-2 targeted probe for magnetic resonance imaging (MRI) of VEGFR-2 in two glioma models in rats (i.e. C6 and RG2). The heterogeneity of VEGFR-2 expression was non-invasively imaged with MRI and validated with various in vitro, in vivo, and ex vivo experiments. Not only was heterogeneous expression of VEGFR-2 found in different glioma tumors, it was also observed in different regions within the same tumor (e.g. tumor periphery, peri-necrotic area, and tumor interior). This report highlights the complex nature of gliomas, which may offer invaluable insights into tumor heterogeneity and potential clinical management of glioma patients. These patients have dismal clinical outcomes and are in urgent need of better tools to improve brain tumor treatment.
Molecular MRI (mMRI); glioma; tumor angiogenesis; VEGFR-2; molecular imaging
Acute kidney injury (AKI) frequently complicates septic shock and independently predicts mortality in this population. Clinical factors alone do not entirely account for differences in risk of AKI between patients. Genetic variants likely explain this differential susceptibility. To identify genetic variants linked to AKI susceptibility, we conducted a high-density genotyping association study in a large population of patients with septic shock.
Tertiary academic medical center.
1,264 patients with septic shock were analyzed to elucidate clinical risk factors associated with the development of AKI. Among them, 887 Caucasian patients were randomly split into discovery and validation cohorts and genotyped using the Illumina Human CVD BeadChip.
Measurements and Main Results
627 of the 1,264 patients with septic shock and 441 of the 887 patients with genotyping data developed AKI within the first 72 hours of ICU admission. Five single nucleotide polymorphisms (SNPs) were associated with AKI in both the discovery and validation cohorts. Two of these were in the BCL2 gene and both were associated with a decreased risk of AKI (rs8094315: OR 0.61, P=0.0002; rs12457893: OR 0.67, P=0.0002, both for combined data). Bcl-2 is involved in the apoptosis pathway, which has previously been implicated in AKI. Another SNP was in the SERPINA4 gene, whose protein product, kallistatin, has been linked to apoptosis in the kidney.
Large-scale genotyping reveals two SNPs in the BCL2 gene and a SNP in the SERPINA4 gene associated with a decreased risk of developing AKI, supporting the putative role of apoptosis in the pathogenesis of AKI.
acute kidney injury; apoptosis; BCL2; SERPINA4; genetic susceptibility; sepsis
Blood–brain barrier (BBB) dysfunction in acute liver failure (ALF) results in increased BBB permeability that often precludes the patients from obtaining a life-saving liver transplantation. It remains controversial whether matrix metalloproteinase-9 (MMP-9) from the injured liver contributes to the deregulation of BBB function in ALF. We selectively upregulated a physiologic inhibitor of MMP-9 (TIMP-1) with a single intracerebroventricular injection of TIMP-1 cDNA plasmids at 48 and 72 hours, or with pegylated-TIMP-1 protein. Acute liver failure was induced with tumor necrosis factor-α and 𝒟-(+)-galactosamine in mice. Permeability of BBB was assessed with sodium fluorescein (NaF) extravasation. We found a significant increase in TIMP-1 within the central nervous system (CNS) after the administration of TIMP-1 cDNA plasmids and that increased TIMP-1 within the CNS resulted in an attenuation of BBB permeability, a reduction in activation of epidermal growth factor receptor and p38 mitogen-activated protein kinase signals, and a restoration of the tight junction protein occludin in mice with experimental ALF. Pegylated TIMP-1 provided similar protection against BBB permeability in mice with ALF. Our results provided a proof of principle that MMP-9 contributes to the BBB dysfunction in ALF and suggests a potential therapeutic role of TIMP-1 in ALF.
acute liver failure; BBB permeability; tight junction; TIMP-1
Cardiac lipomatous metaplasia (LM) occurs in patients with chronic ischemic heart disease and heart failure with unclear mechanisms. We studied coronary occlusion/reperfusion-induced myocardial infarction (MI) in rabbits during a 9-months follow-up using 3.0 T magnetic resonance scanner, and confirmed the presence of MI in acute phase and LM in chronic phase using histopathology.
MI was surgically induced in 10 rabbits by 90-min coronary artery occlusion and reperfusion. Forty-eight hours later, multiparametric cardiac magnetic resonance imaging (cMRI) was performed at a 3.0 T clinical scanner for MI diagnosis and cardiac function analysis. Afterwards, seven rabbits were scarified for histochemical staining with triphenyltetrazolium chloride (TTC), and hematoxylin-eosin (HE), and 3 were scanned with cMRI at 2 days, 2 weeks, 2 months and 9 months for longitudinal observations of morphological and functional changes, and the fate of the animals. Post-mortem TTC, HE and Masson's trichrome (MTC) were studied for chronic stage of MI.
The size of acute MI correlated well between cMRI and TTC staining (r2=0.83). Global cardiac morphology-function analysis showed significant correlation between increasing acute MI size and decreasing ejection fraction (p<0.001). During 9 months, cMRI documented evolving morphological and functional changes from acute MI to chronic scar transformation and fat deposition with a definite diagnosis of LM established by histopathology.
Acute MI and chronic LM were induced in rabbits and monitored with 3.0 T MRI. Studies on this platform may help investigate the mechanisms and therapeutic interventions for LM.
Acute myocardial infarction; Animal model; Chronic ischemia; Cardiovascular magnetic resonance imaging; Lipomatous metaplasia
The human pathogens enteropathogenic Escherichia coli (EPEC) and vaccinia virus trigger actin assembly in host cells by activating the host adaptor Nck and the actin nucleation promoter neural Wiskott-Aldrich syndrome protein (N-WASP). EPEC translocates effector molecules into host cells via type III secretion, and the interaction between the translocated intimin receptor (Tir) and the bacterial membrane protein intimin stimulates Nck and N-WASP recruitment, leading to the formation of actin pedestals beneath adherent bacteria. Vaccinia virus also recruits Nck and N-WASP to generate actin tails that promote cell-to-cell spread of the virus. In addition to Nck and N-WASP, WASP-interacting protein (WIP) localizes to vaccinia virus tails, and inhibition of actin tail formation upon ectopic expression of WIP mutants led to the suggestion that WIP is required for this process. Similar studies of WIP mutants, however, did not affect the ability of EPEC to form actin pedestals, arguing against an essential role for WIP in EPEC-induced actin assembly. In this study, we demonstrate that Nck and N-WASP are normally recruited by vaccinia virus and EPEC in the absence of WIP, and neither WIP nor the WIP family members CR16 and WIRE/WICH are essential for pathogen induced actin assembly. In addition, although Nck binds EPEC Tir directly, N-WASP is required for its localization during pedestal formation. Overall, these data highlight similar pathogenic strategies shared by EPEC and vaccinia virus by demonstrating a requirement for both Nck and N-WASP, but not WIP or WIP family members in pathogen-induced actin assembly.
Porcine epidemic diarrhea virus (PEDV) infection, which causes acute diarrhea and dehydration in suckling piglets, has become a serious problem for the swine industry of China in recent years. In this study, a virulent PEDV strain, GD-1, was obtained from fecal samples from suckling piglets that suffered from severe diarrhea in 2011 in Guangdong, China. Here we describe the complete genome sequence of strain GD-1, which may be helpful in further understanding the molecular epidemiology and genetic diversity of PEDV field isolates in China.
Recently, nephropathogenic infectious bronchitis virus (IBV) outbreaks have occurred in commercial broiler flocks and have been associated with a high incidence and morbidity in China. The CK/CH/Zhejiang/06/10 strain (IBV-YX10) was isolated from a 12-day-old broiler chicken in a flock of chickens with swollen speckled kidneys and distended ureters filled with uric acid in China in 2010. Here we reported the complete genomic sequence of the IBV-YX10 which was a natural recombinant nephropathogenic infectious bronchitis virus strain. These findings will contribute additional insights into the molecular characteristics of evolving IBV genomes and the need for effective control of IBV in China.
A series of doxorubicin-loaded polymer-caged nanobins (PCNDXR) were evaluated in vivo in a murine MDA-MB-231 xenograft model of triple-negative breast cancer. The cross-linked polymer cage in PCNDXR offers protection for the drug payload while serving as a pH-responsive trigger that enhances drug release in the acidic environments commonly seen in solid tumors and endosomes. Varying the degree of cross-linking in the polymer cage allows the surface potential of PCNDXR, and thus the in vivo circulation lifetime of the nanocarriers, to be tuned. Given these design advantages, the present study provides the first in vivo evidence that PCNDXR can effectively inhibit tumor growth in a murine model of breast cancer. Importantly, PCNDXR was well-tolerated by mice, and drug encapsulation attenuated the toxicity of free doxorubicin. Taken together, this study demonstrates the potential utility of the PCN platform in cancer therapy.
Liposomes; Polymers; Breast Cancer; pH-Responsive Release; In Vivo Drug Delivery
The NADPH oxidases (Nox) are a family of transmembrane oxidoreductases that produce superoxide and other reactive oxygen species (ROS). Nox5 was the last of the conventional Nox isoforms to be identified and is a calcium-dependent enzyme that does not depend on accessory subunits for activation. Recently, Nox5 was shown to be expressed in human blood vessels and therefore the goal of current study was to determine whether nitric oxide (NO) can modulate Nox5 activity. Endogenously produced NO potently inhibited basal and stimulated Nox5 activity and inhibition was reversible with chronic, but not acute exposure to L-NAME. Nox5 activity was reduced by NO donors, iNOS, eNOS and in endothelial cells and LPS-stimulated smooth muscle cells in a manner dependent on NO concentration. ROS production was diminished by NO in an isolated enzyme activity assay replete with surplus calcium and NADPH. There was no evidence for NO-dependent changes in tyrosine nitration, glutathiolation or phosphorylation of Nox5. In contrast, there was evidence for the increased nitrosylation of Nox5 as determined by the biotin-switch assay and mass spectrometry. Four S-nitrosylation sites were identified and of these, mutation of C694 dramatically lowered Nox5 activity, NO-sensitivity and biotin-labeling. Furthermore, co-expression of the denitrosylation enzymes thioredoxin (Trx1) and GSNO reductase (GSNOR) prevented NO-dependent inhibition of Nox5. The potency of NO against other Nox enzymes was Nox1≥Nox3>Nox5>Nox2 whereas Nox4 was refractory. Collectively, these results suggest that endogenously produced NO can directly S-nitrosylate and inhibit the activity of Nox5.
Nitric oxide; NADPH oxidase; S-nitrosylation; Reactive Oxygen Species; Nox5
A novel isolate of infectious bursal disease virus (IBDV) was designated GX-NN-L. The GX-NN-L IBDV was a very virulent infectious bursal disease virus (vvIBDV) isolated from broiler flocks in Guangxi province, China, in 2011. The GX-NN-L IBDV caused high mortality, immunosuppression, low weight gain, and bursal atrophy in commercial broilers. Here, we report the complete genome sequence of the GX-NN-L IBDV, a reassortment strain with segments A and B derived from very virulent strains and attenuated IBDV, respectively. These findings from this study provide additional insights into the genetic exchange between attenuated and very virulent strains of IBDV and continuous monitoring of the spread of the virus in chicken.
Porcine circovirus type 2 (PCV2) is the etiologic agent of porcine circovirus-associated disease, and it is mainly divided into five genotypes. Here, we report the complete genome sequence of PCV2 strain GDYX, which belongs to PCV2d and has a unique amino acid variation at position 169 (S to G).